fix(agent-rows): preserve same-tab child labels

src/renderer/src/components/dashboard/use-agent-row-conversation-name.test.ts

@@ -56,6 +56,44 @@ describe('useAgentRowConversationName', () => {
     expect(useAgentRowConversationName(makeAgent({ rowSource: 'subagent' }))).toBeNull()
   })
 
+  it('does not inherit a same-tab lineage parent conversation name', () => {
+    const tabsByWorktree = new Proxy(
+      {},
+      {
+        get: () => {
+          throw new Error('same-tab child rows must not read the parent tab')
+        }
+      }
+    )
+    storeState.current = { settings: {}, tabsByWorktree }
+    expect(
+      useAgentRowConversationName(
+        makeAgent({
+          entry: {
+            prompt: 'child prompt',
+            orchestration: {
+              parentPaneKey: 'tab-1:aaaaaaaa-aaaa-4aaa-8aaa-aaaaaaaaaaaa'
+            }
+          },
+          lineage: { depth: 1, isFirstSibling: true, isLastSibling: true, childCount: 0 }
+        } as Partial<DashboardAgentRow>)
+      )
+    ).toBeNull()
+  })
+
+  it('uses a lineage child conversation name when it owns a separate tab', () => {
+    const agent = makeAgent({
+      entry: {
+        prompt: 'child prompt',
+        orchestration: {
+          parentPaneKey: 'parent-tab:aaaaaaaa-aaaa-4aaa-8aaa-aaaaaaaaaaaa'
+        }
+      },
+      lineage: { depth: 1, isFirstSibling: true, isLastSibling: true, childCount: 0 }
+    } as Partial<DashboardAgentRow>)
+    expect(useAgentRowConversationName(agent)).toBe('Patient sync spike')
+  })
+
   it('indexes one immutable tab array once across rows', () => {
     let tabReads = 0
     const tabs = new Proxy(

src/renderer/src/components/dashboard/use-agent-row-conversation-name.ts

@@ -1,4 +1,5 @@
 import { getAgentRowConversationName } from '../../../../shared/agent-row-conversation-name'
+import { parsePaneKey } from '../../../../shared/stable-pane-id'
 import { useAppStore } from '@/store'
 import type { AppState } from '@/store/types'
 import type { DashboardAgentRow } from './useDashboardData'
@@ -24,15 +25,22 @@ function getIndexedTab(
 
 /** The row's conversation name, or null when nothing usable exists. */
 export function useAgentRowConversationName(agent: DashboardAgentRow): string | null {
-  const isSubagent = agent.rowSource === 'subagent'
+  const parentPaneKey = agent.entry.orchestration?.parentPaneKey
+  const usesParentTab =
+    agent.lineage?.depth === 1 &&
+    parentPaneKey !== undefined &&
+    parsePaneKey(parentPaneKey)?.tabId === agent.tab.id
+  const cannotOwnTabName = agent.rowSource === 'subagent' || usesParentTab
   const generatedTitlesEnabled = useAppStore(
-    (s) => !isSubagent && s.settings?.tabAutoGenerateTitle === true
+    (s) => !cannotOwnTabName && s.settings?.tabAutoGenerateTitle === true
   )
-  // Why: child rows describe the child, so the parent tab would mislabel them.
   const liveTab = useAppStore((s) =>
-    isSubagent ? undefined : getIndexedTab(s.tabsByWorktree[agent.tab.worktreeId], agent.tab.id)
+    cannotOwnTabName
+      ? undefined
+      : getIndexedTab(s.tabsByWorktree[agent.tab.worktreeId], agent.tab.id)
   )
-  if (isSubagent) {
+  // Why: synthetic and same-tab child rows do not own the parent tab's name.
+  if (cannotOwnTabName) {
     return null
   }
   // Why: retained row snapshots need a fallback after their live tab disappears.

src/renderer/src/components/sidebar/WorktreeList.lineage-agent-expansion-coupling.test.tsx

@@ -474,8 +474,9 @@ describe('WorktreeCard agent-list <-> child-worktrees expansion coupling', () =>
     setAgentLineageState({ agentActivityDisplayMode: 'full' })
     const { container } = await renderWorktreeList()
 
-    // Sanity: real agent rows rendered (parent + its lineage child agent).
-    expect(container.textContent).toContain('PARENT_AGENT_PROMPT')
+    // Same-tab lineage children must not inherit the parent's conversation name.
+    expect(container.textContent).toContain('Parent Terminal')
+    expect(container.textContent).not.toContain('PARENT_AGENT_PROMPT')
     expect(container.textContent).toContain('CHILD_AGENT_PROMPT')
 
     // Both controls exist and are independent DOM elements.